Surgical stapling device with replaceable reload assembly

ABSTRACT

A surgical stapling device includes an adapter assembly and a reload assembly. The adapter assembly includes an elongate body and a channel member coupled to the elongate body. The reload assembly includes an anvil and a cartridge assembly that includes a cartridge body and a channel extension. A proximal portion of the cartridge body is received within the channel member to secure the reload assembly to the adapter assembly. The channel extension is received about a distal portion of the cartridge body and is engaged with the channel member to support the cartridge body.

FIELD

This technology is generally related to surgical stapling devices, and more particularly, to surgical stapling devices including replaceable reload assemblies.

BACKGROUND

Surgical stapling devices for endoscopic use are well known and commonly used to minimize patient trauma and reduce patient recovery times. Typically, endoscopic stapling devices include a tool assembly that has an anvil and a cartridge assembly that are coupled to each other by a pivot member and movable in relation to each other between open and clamped positions. The cartridge assembly includes a staple cartridge that supports a plurality of staples. In order to facilitate reuse of the surgical stapling device and reduce costs associated with a surgical procedure, it is known to include the tool assembly as part of a replaceable reload assembly that can be replaced after each firing of the surgical stapling device. It is also known to include a replaceable staple cartridge on the cartridge assembly that can be replaced to facilitate reuse of the surgical stapling device.

Typically, a reload assembly includes the tool assembly and a proximal body portion that supports a drive assembly for actuating the tool assembly. Replacement of the entire reload assembly after each firing of the surgical stapling device can be costly. The staple cartridge typically includes a cartridge body that supports a plurality of surgical staples and an actuation sled. The cartridge body is flimsy and sometimes difficult to handle.

A continuing need exists for a surgical stapling device that includes an inexpensive, more robust reload assembly that can be easily replaced to facilitate reuse of the surgical stapling device.

SUMMARY

One aspect of this disclosure is directed to a surgical stapling device which includes an adapter assembly and a reload assembly. The adapter assembly includes an elongate body and a channel member. The elongate body defines a longitudinal axis and has a proximal portion and a distal portion. The channel member is supported on the distal portion of the elongate body and includes a base wall and side walls that define a cavity. The channel member is movable in relation to the elongate body about an axis transverse to the longitudinal axis between a first position aligned with the longitudinal axis and a second position defining an acute angle with respect to the longitudinal axis. The reload assembly includes an anvil and a cartridge assembly pivotably coupled to the anvil. The cartridge assembly includes a cartridge body and a plurality of staples. The cartridge body has a proximal portion and a distal portion and defines a central knife slot and staple pockets positioned on each side of the central knife slot. Each of the plurality of staples is received within one of the staple pockets. The cartridge body is releasably received within the cavity defined by the channel member to mount the reload assembly to the adapter assembly.

In aspects of the disclosure, the anvil includes an anvil body having a proximal portion including spaced flange portions that define a recess and a distal portion, and the proximal portion of the cartridge body is received within the recess in the proximal portion of the anvil body.

In some aspects of the disclosure, the proximal portion of the anvil body includes spaced fingers that are positioned within the recess and the proximal portion of the cartridge body defines spaced slots, wherein the spaced fingers are received within the spaced slots to pivotably couple the anvil to the cartridge assembly.

In certain aspects of the disclosure, the spaced fingers and the spaced slots are curved.

In aspects of the disclosure, the side walls of the channel member of the adapter assembly include an elongated tab and the spaced flange portions of the of the anvil body define slots, and the slots in the spaced flange portions of the anvil body receive the elongated tabs of the channel member to secure the reload assembly to the adapter assembly.

In some aspects of the disclosure, the adapter assembly includes a biasing member that is positioned to urge the channel member towards its first position.

In certain aspects of the disclosure, the elongated tab and the slots are positioned and configured such that the channel member must be pivoted towards its second position against the bias of the biasing member to position the elongated tab within the slots in the spaced flange portions of the anvil body.

In aspects of the disclosure, the cartridge assembly includes a channel extension that is supported on the distal portion of the cartridge body, and the channel extension is positioned in abutting relation with the channel member of the adapter assembly when the reload assembly is mounted to the channel member.

In some aspects of the disclosure, the channel extension includes a base wall and side walls that define a cavity, and the cavity defined by the channel extension is aligned with the cavity defined by the channel member when the reload assembly is mounted on the channel member of the adapter assembly.

In certain aspects of the disclosure, the cavity of the channel extension receives the distal portion of the cartridge body.

In aspects of the disclosure, the base wall of the channel extension defines a cutout in a proximal end of the base wall and the base wall of the channel member includes a distal portion that is received within the cutout when the reload assembly is mounted on the channel member of the adapter assembly.

In some aspects of the disclosure, the adapter assembly includes a mounting assembly for non-removably coupling the channel member to the elongate body of the adapter assembly.

Other aspects of the disclosure are directed to an adapter assembly including an elongate body, a mounting assembly, and a channel member. The elongate body defines a longitudinal axis and has a proximal portion and a distal portion. The channel member is supported on the distal portion of the elongate body by the mounting assembly and includes a base wall and side walls that define a cavity that is configured to receive a cartridge body of a cartridge assembly of a surgical stapling device. The channel member is movable in relation to the elongate body about an axis transverse to the longitudinal axis between a first position aligned with the longitudinal axis and a second position defining an acute angle with respect to the longitudinal axis.

In aspects of the disclosure, the mounting assembly non-removably couples the channel member to the elongate body.

In some aspects of the disclosure, the adapter assembly includes a biasing member that is positioned to urge the channel member towards its first position.

Other aspects of the disclosure are directed to a reload assembly including an anvil and a cartridge assembly that is pivotably coupled to the anvil. The cartridge assembly includes a cartridge body, a channel extension and a plurality of staples. The cartridge body has a proximal portion and a distal portion and defines a central knife slot and staple pockets positioned on each side of the central knife slot. Each of the plurality of staples is received within one of the staple pockets. The channel extension includes a base wall and side walls that define a cavity. The cavity receives the distal portion of the cartridge body and is spaced from the proximal portion of the cartridge body.

Other features of the disclosure will be appreciated from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the disclosed surgical stapling device are described herein below with reference to the drawings, wherein:

FIG. 1 is a side perspective view of a surgical stapling device according to aspects of the disclosure including a 60 mm reload assembly;

FIG. 2 is a side perspective view of an adapter assembly and the 60 mm reload assembly of the surgical stapling device shown in FIG. 1 with the 60 mm reload assembly of the tool assembly separated from the adapter assembly;

FIG. 3 is an enlarged view of the indicated area of detail shown in FIG. 2;

FIG. 4 is a side perspective exploded view of a distal portion of the adapter assembly shown in FIG. 2;

FIG. 5 is a cross-sectional view taken along section line 5-5 of FIG. 3;

FIG. 6 is a side perspective exploded view of the 60 mm reload assembly of the surgical stapling device shown in FIG. 1;

FIG. 7 is a bottom perspective view of the anvil of the 60 mm reload assembly shown in FIG. 6;

FIG. 8 is a top perspective view of a channel extension of the 60 mm reload assembly shown in FIG. 6;

FIG. 9 is a bottom perspective view of the channel extension of the 60 mm reload assembly shown in FIG. 6;

FIG. 10 is a cross-sectional view taken along section line 10-10 of FIG. 3;

FIG. 11 is a side view of the distal portion of the surgical stapling device shown in FIG. 1 as the 60 mm reload assembly is being installed the adapter assembly;

FIG. 12 is a side view of the distal portion of the surgical stapling device shown in FIG. 1 with the 60 mm reload assembly coupled to the adapter assembly;

FIG. 13 is a bottom perspective view of a distal portion of the surgical stapling device;

FIG. 14 is an enlarged view of the indicated area of detail shown in FIG. 1 illustrating the distal portion of the surgical stapling device shown in FIG. 1;

FIG. 15 is a cross-sectional view taken along section line 15-15 of FIG. 1;

FIG. 16 is side perspective view of a 45 mm reload assembly according to aspects of the disclosure;

FIG. 17 is a side perspective view of the 45 mm reload assembly shown in FIG. 16 installed onto the adapter assembly of the surgical stapling device of FIG. 1;

FIG. 18 is side perspective view of a 30 mm reload assembly according to aspects of the disclosure; and

FIG. 19 is a side perspective view of the 30 mm reload assembly shown in FIG. 18 installed onto the adapter assembly of the surgical stapling device of FIG. 1; and

FIG. 20 is a side perspective view of the distal portion of the surgical stapling device shown in FIG. 1 with an alternative version of the reload assembly.

DETAILED DESCRIPTION

The disclosed surgical stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that disclosed aspects of the surgical stapling device are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure. In addition, directional terms such as front, rear, upper, lower, top, bottom, distal, proximal, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure. As used herein, the terms “parallel”, “perpendicular”, and “aligned” are understood to include relative configurations that are substantially parallel, substantially perpendicular, and substantially aligned, i.e., up to about + or −10 degrees from true parallel, true perpendicular, true alignment.

The disclosure is directed to a surgical stapling device includes an adapter assembly and a reload assembly. The adapter assembly includes an elongate body and a channel member coupled to the elongate body. The reload assembly includes an anvil and a cartridge assembly that includes a cartridge body and a channel extension. A proximal portion of the cartridge body is received within the channel member to secure the reload assembly to the adapter assembly. The channel extension is received about a distal portion of the cartridge body and is engaged with the channel member to support the cartridge body.

FIG. 1 illustrates a surgical stapling device shown generally as stapling device 10 that includes a handle assembly 12, an adapter assembly 14, and a reload assembly 16. The handle assembly 12 is powered and includes a stationary handgrip 18 and actuation buttons 20. The actuation buttons 20 are operable to actuate various functions of the reload assembly 16 via the adapter assembly 14, i.e., approximation of the reload assembly, and stapling and cutting of tissue. In certain aspects of the disclosure, the handle assembly 12 supports batteries (not shown) that provide power to the handle assembly 12 to operate the stapling device 10. Although the stapling device 10 is illustrated as a powered stapling device, it is envisioned that the advantages of this disclosure are suitable for use with manually powered surgical stapling devices as well as robotically controlled stapling devices. U.S. Pat. No. 5,865,361 (“'361 Patent”) describes a stapling device that describes exemplary aspects of a manually powered stapling device including a reload assembly that is releasably coupled to a body portion of the stapling device.

FIGS. 2-5 illustrate the adapter assembly 14 of the surgical stapling device 10 (FIG. 1) which includes an elongate body 22, a mounting assembly 24, a rotation knob 26, a channel member 30, and a proximal hub portion 32. The elongate body 22 defines a longitudinal axis “X” (FIG. 2) and has a proximal portion 34 and a distal portion 36. The proximal hub portion 32 of the adapter assembly 14 is releasably coupled to the handle assembly 12 (FIG. 1) and supports the rotation knob 26. The proximal portion 34 of the elongate body 22 is supported by the rotation knob 26 such that rotation of the rotation knob 26 about the proximal hub portion 32 of adapter assembly 14 causes rotation of the elongate body 22 and the tool assembly 16 about the longitudinal axis “X” of the elongate body 22 in relation to the proximal bub portion 32 of the adapter assembly 14 and the handle assembly 12. The mounting assembly 24 is pivotably secured to the distal portion 36 of the elongate body 22 about a vertical axis “Z” as viewed in FIG. 3 and is coupled to the channel member 30 to pivotally secure the channel member 30 to the distal portion 36 of the elongate body 22 about the axis “Z”. In aspects of the disclosure, the channel member 30 is non-removably coupled to the elongate body 22 by the mounting assembly 24. The channel member 30 is pivotably coupled to the mounting assembly 24 about a horizontal axis “Y” defined by pivot members 42 as viewed in FIG. 3 to facilitate pivotal movement of the channel 30 from a first position (FIG. 3) substantially longitudinally aligned with the longitudinal axis “X” and angled downwardly from the longitudinal axis “X” to a second position extending parallel to and substantially longitudinally aligned with the longitudinal axis “X” of the elongate body 22.

The channel member 30 includes a body 50 including a base wall 52 and side walls 54 that define a cavity 56. The base wall 52 includes a distal portion 52 a that extends distally beyond the side walls 54 (FIG. 5) and defines a T-shaped channel 58 that receives a working end 60 (FIG. 3) of a drive assembly of the stapling device 10. The '361 Patent discloses stapling device including exemplary aspects of a drive assembly that is suitable for use with the disclosed reload assembly 16. The cavity 56 of the channel member 30 releasably receives a staple cartridge of the reload assembly 16 as described in further detail below. In some aspects of the disclosure, each of the side walls 54 of the channel member 30 includes an outer surface that has an elongated tab 54 a that extends from adjacent the base wall 52 of the channel member 30 to the upper end of the side wall 54.

The adapter assembly 14 includes first biasing members 64 (FIG. 4). Each of the first biasing members 64 has a proximal end supported on the mounting assembly 24 and a distal end that extends into the cavity 56 defined by the channel member 30. The distal ends of the biasing members 64 are positioned to engage the reload assembly 16 when the reload assembly 16 is coupled to the channel member 30 of the adapter assembly 14 to urge channel member 30 towards its first position and urge the reload assembly 16 to an open position as described in further detail below. In aspects of the disclosure, the first biasing members 64 are in the form of leaf springs although it is envisioned that the first biasing members 64 may have other configurations.

The adapter assembly 14 also includes second biasing members 66. Each of the second biasing members 66 (FIG. 5) includes a proximal end that is received within a bore 68 formed in the mounting assembly 24 and a distal end that is received in a bore 70 formed in the proximal portion of the channel member 30. The second biasing members 66 which may be in the form of coil springs urge the channel member 30 towards its second position aligned with the longitudinal axis “X” of the elongate body 22. Alternately, the second biasing members 66 may have other configurations.

FIGS. 6-10 illustrate the reload assembly 16 of the stapling device 10 (FIG. 1) which includes a cartridge assembly 80 and an anvil 82. Each of the cartridge and anvil assemblies 80 and 82 includes a proximal portion and a distal portion. The cartridge assembly 80 and the anvil 82 are coupled together such that the reload assembly 16 can pivot between an open position (FIG. 1) in which the distal portions of the cartridge and anvil assemblies 80 and 82 are spaced from each other and a clamped position in which the cartridge and anvil assemblies 80 and 82 are in juxtaposed alignment (FIG. 20).

The cartridge assembly 80 includes a cartridge body 84, a channel extension 86, a staple guard 88, staple pushers 90, an actuation sled 92, and staples 94. The cartridge body 84 has a tissue engaging surface 96 and defines a central knife slot 98 and a plurality of staple pockets 100 positioned on each side of the central knife slot 98. Each of the staple pockets 100 receives a staple 94 and one of the pushers 90. The actuation sled 92 is movable within the cartridge body 84 from a retracted position to an advanced position to drive the pushers 90 upwardly as viewed in FIG. 6 from within the cartridge body 84 towards the tissue engaging surface 96 of the cartridge body 84 to eject the staples 94 from within the staple pockets 100 of the cartridge body 84. Although the cartridge body 84 is illustrated as being linear, it is envisioned that the cartridge body 84 may have a non-linear configuration along its longitudinal axis. The cartridge body 84 has a proximal portion that defines curved slots 104 that are provided to pivotably couple the cartridge assembly 80 to the anvil 82 as described in further detail below.

The staple guard 88 is secured to a lower side of the cartridge body 84 opposite to the tissue engaging surface 96 and provides a cover to prevent the pushers 90 and the staples 94 from falling from the lower side of the cartridge body 84. In certain aspects of the disclosure, the staple guard 88 includes openings 110 that receive projections 112 on the cartridge body 84 such that the staple guard 88 can be snap-fit onto the cartridge body 84. In aspects of the disclosure, each of the projections 112 includes an angled surface 112 a that allows portions of the staple guard 88 to be cammed outwardly past the projections 112 as the staple guard 88 is attached to the cartridge body 84. Additional detents 113 can also be provided on the staple guard 88 to further secure the staple guard 88 to the cartridge body 84. The staple guard 88 defines a knife slot 114 that is aligned with the knife slot 98 formed in the cartridge body 92.

The channel extension 86 includes a base wall 120 and side walls 122 that define a cavity 124. The base wall 120 includes a cutout or notch 120 a (FIG. 8) at its proximal end. The cavity 124 receives a distal portion of the cartridge body 84 unless the cartridge body is 30 mm or less. In a reload assembly including a cartridge body 84 that is 30 mm or less, the cartridge assembly 80 of the reload assembly 16 is wholly received within the channel member 30 and does not include a channel extension 86 as described in further detail below. The side walls 122 of the channel extension 86 define cutouts 126 that receive projections 128 of the cartridge body 84 to secure the cartridge body 84 within the channel 124 of the channel member 86. One of the side walls 122 also includes an inner surface that defines a slot 130 that receives a projection formed on an outer surface of the cartridge body 84 to help secure the channel extension 86 on the cartridge body 84.

The anvil 82 includes an anvil body 140 that has a proximal portion 142 and a distal portion 144. The proximal portion 142 is substantially U-shaped and includes spaced flange portions 146 that define a recess 148 that receives the proximal portion of the cartridge assembly 80. In some aspects of the disclosure, the spaced flange portions 146 of the anvil body 84 define slots 146 a. The proximal portion 142 includes an inner surface 142 a (FIG. 7) that faces the cartridge assembly 80 and two spaced fingers 150 (FIG. 7) that extend from the inner surface 142 a towards the cartridge assembly 80. The spaced fingers 150 are curved and are received within the curved slots 104 (FIG. 10) defined within the proximal portion of the cartridge body 84 of the cartridge assembly 80. Receipt of the spaced fingers 150 within the curved slots 104 pivotally couples the anvil assembly 82 to the cartridge assembly 80 such that the cartridge and anvil assemblies 80 and 82 are movable in relation to each other between open and clamped positions.

The anvil body 140 includes a staple forming surface 154 that extends from the proximal portion 142 of the anvil body 140 to the distal portion 144 of the anvil body 140 and faces the cartridge assembly 80. The staple forming surface 154 defines a knife slot 156 and a plurality of staple forming pockets 160 that are in juxtaposed alignment with the cartridge body 84 of the cartridge assembly 80 when the cartridge and anvil assemblies 80 and 82 are in the clamped position. The knife slot 156 communicates with a channel 162 (FIG. 7) defined within the anvil body 84 that receives a portion of the working end 60 (FIG. 3) of the drive assembly of the adapter assembly 14 of the stapling device 10 when the stapling device 10 is fired. The '361 Patent discloses an exemplary drive assembly including a working end suitable for use with the disclosed reload assembly 16.

When the cartridge assembly 80 and the anvil 82 are assembled, the proximal portion of the cartridge assembly 80 is positioned between the spaced flange portions 146 of the anvil body 140 and the spaced fingers 150 of the anvil body 140 are received within the curved slots 104 of the cartridge body 84. The configuration of the slots 104 and the fingers 150 allow the cartridge assembly 80 to pivot in relation to the anvil 82 between the open position (FIG. 10) and a clamped position (FIG. 20) in which the staple forming surface 154 of the anvil 80 is positioned in juxtaposed alignment with the tissue engaging surface 96 of the cartridge body 84.

FIGS. 11-15 illustrate the reload assembly 16 as the reload assembly 16 is mounted onto the channel 30 of the adapter assembly 14 (FIG. 3). As described above, the second biasing members 66 urge the channel member 30 towards a position in which the channel member 30 is aligned with the longitudinal axis “X” of the elongate body 22 of the adapter assembly 14. In this position, the tabs 54 a on the side walls 54 of the channel member 30 are positioned to engage the spaced flange portions 146 of the anvil body 140. In order to mount the reload assembly 30 onto the channel member 30 of the adapter assembly 14, the channel member 30 is pivoted against the bias of the second biasing members 66 in the direction of arrow “A” in FIG. 11 to move the tabs 54 a out of alignment with the spaced flange portions 146 of the anvil body 140. Next, the reload assembly 16 is moved longitudinally in the direction of arrow “B” in FIG. 11 into engagement with the mounting assembly 24. When the tabs 54 a are aligned with the slots 146 a in the spaced flanges 146 of the anvil body 140, the channel member 30 is released to allow the tabs 54 a of the channel member 30 to pivot in the direction indicated by arrow “C” in FIG. 12 into the slots 146 a of the anvil body 140 to secure the reload assembly 16 to the channel member 30 of the adapter assembly 14.

When the reload assembly 16 is secured to the channel member 30 of the adapter assembly 14, the channel extension 86 of the reload assembly 16 is in abutting relation to the channel member 30 of the adapter assembly 14 and the distal portion 52 a of the base wall 52 of the channel member 30 is received within the cutout 120 a of the channel extension 86. In this position, the first biasing members 64 engage the cartridge body 84 of the cartridge assembly 80 to urge the cartridge assembly 80 away from the anvil assembly 80. This has the effect of urging the channel member 30 towards its second position misaligned with the longitudinal axis “X” of the elongate body 22 of the adapter assembly 14 to move the reload assembly 16 to the open position (FIG. 14).

In aspects of the disclosure, the channel member 30 of the adapter assembly 14 is adapted to receive 30 mm, 45 mm, and 60 mm reload assemblies. FIGS. 1-15 illustrate the stapling device 10 with a 60 mm reload assembly 16. The channel member 30 has a length (approximately 30 mm) to receive the proximal portion of the cartridge body 84 of a 60 mm reload assembly 16 and the channel extension 86 receives the distal portion of the cartridge body 84. Since the adapter assembly 14 can be used with multiple size reload assemblies 16, the size of the channel extension 86 will vary based upon the size of the reload assembly. For example, FIGS. 16 and 17 illustrate the channel member 30 of the adapter assembly 14 with a 45 mm reload assembly 216 mounted to the channel member 30. As illustrated, when a 45 mm reload assembly 216 is mounted on the channel member 30, the channel extension 286 has a shorter length (approximately 15 mm) than the channel extension 86 (FIG. 12) of the reload assembly 16. This is because the length of the channel member 30 is the same regardless of what size reload assembly is mounted on the adapter assembly 14. Similarly, as illustrated in FIGS. 18 and 19, when a 30 mm reload assembly 316 is mounted onto the channel member 30 of the adapter assembly 14, the reload assembly 316 does not include a channel extension because the cartridge body 384 of the reload assembly 316 is fully supported within the channel member 30 of the adapter assembly 14.

FIG. 20 illustrates an alternative version of the disclosed and adapter assembly and reload assembly shown generally as adapter assembly 414 and reload assembly 416. The adapter assembly 414 and the reload assembly 416 are substantially identical to the adapter assembly 14 and reload assembly 16 except that the channel member 430 of the adapter assembly 414 and the channel extension 486 of the reload assembly 416 include additional interlocking structure to maintain alignment between the channel member 430 and the channel extension 486 when the reload assembly 416 is mounted onto the channel member 430. More specifically, the channel member 430 of the adapter assembly 414 includes a distal portion that defines longitudinal recesses 430 a (only one is shown) and the channel extension 486 of the reload assembly 416 includes proximally extending fingers 486 a (only one is shown) that are received within the longitudinal recesses 430 a to maintain alignment between the channel member 430 and the channel extension 486 when the reload assembly 416 is mounted onto the channel member 430. Although the longitudinal recesses 430 are shown in the channel member 430 and the proximally extending fingers 486 a are shown on the channel extension 486, it is envisioned that these features could be reversed. It is also envisioned that one or more fingers and recesses of varying shapes could be provided to ensure alignment between the channel member 430 and the channel extension 486.

Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary aspects of the disclosure. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described aspects of the disclosure. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. 

What is claimed is:
 1. A surgical stapling device comprising: an adapter assembly including an elongate body defining a longitudinal axis and having a proximal portion and a distal portion, and a channel member supported on the distal portion of the elongate body, the channel member including a base wall and side walls that define a cavity, the channel member being movable in relation to the elongate body about an axis transverse to the longitudinal axis between a first position aligned with the longitudinal axis and a second position defining an acute angle with respect to the longitudinal axis; and a reload assembly including an anvil and a cartridge assembly pivotably coupled to the anvil, the cartridge assembly including a cartridge body and a plurality of staples, the cartridge body having a proximal portion and a distal portion and defining a central knife slot and staple pockets positioned on each side of the central knife slot, each of the plurality of staples received within one of the staple pockets, wherein the cartridge body is releasably received within the cavity defined by the channel member to mount the reload assembly to the adapter assembly.
 2. The surgical stapling device of claim 1, wherein the anvil includes an anvil body having a proximal portion and a distal portion, the proximal portion of the anvil body including spaced flange portions that define a recess, the proximal portion of the cartridge body received within the recess in the proximal portion of the anvil body.
 3. The surgical stapling device of claim 2, wherein the proximal portion of the anvil body includes spaced fingers that are positioned within the recess and the proximal portion of the cartridge body defines spaced slots, the spaced fingers received within the spaced slots to pivotably couple the anvil to the cartridge assembly.
 4. The surgical stapling device of claim 3, wherein the spaced fingers and the spaced slots are curved.
 5. The surgical stapling device of claim 2, wherein the side walls of the channel member of the adapter assembly include an elongated tab and the spaced flange portions of the of the anvil body define slots, the slots in the spaced flange portions of the anvil body receiving the elongated tabs of the channel member to secure the reload assembly to the adapter assembly.
 6. The surgical stapling device of claim 5, wherein the adapter assembly includes a biasing member that is positioned to urge the channel member towards its first position.
 7. The surgical stapling device of claim 6, wherein the elongated tab and the slots are positioned and configured such that the channel member must be pivoted towards its second position against the bias of the biasing member to position the elongated tab within the slots in the spaced flange portions of the anvil body.
 8. The surgical stapling device of claim 1, wherein the cartridge assembly includes a channel extension supported on the distal portion of the cartridge body, the channel extension positioned in abutting relation with the channel member of the adapter assembly when the reload assembly is mounted to the channel member.
 9. The surgical stapling device of claim 8, wherein the channel extension includes a base wall and side walls that define a cavity, the cavity defined by the channel extension aligned with the cavity defined by the channel member when the reload assembly is mounted on the channel member of the adapter assembly, the cavity of the channel extension receiving the distal portion of the cartridge body.
 10. The surgical stapling device of claim 9, wherein the base wall of the channel extension defines a cutout in a proximal end of the base wall and the base wall of the channel member includes a distal portion that is received within the cutout when the reload assembly is mounted on the channel member of the adapter assembly.
 11. The surgical stapling device of claim 1, wherein the adapter assembly includes a mounting assembly for non-removably coupling the channel member to the elongate body of the adapter assembly.
 12. An adapter assembly comprising: an elongate body defining a longitudinal axis and having a proximal portion and a distal portion, a mounting assembly, and a channel member supported on the distal portion of the elongate body by the mounting assembly, the channel member including a base wall and side walls that define a cavity configured to receive a cartridge body of a cartridge assembly of a surgical stapling device, the channel member being movable in relation to the elongate body about an axis transverse to the longitudinal axis between a first position aligned with the longitudinal axis and a second position defining an acute angle with respect to the longitudinal axis.
 13. The adapter assembly of claim 12, wherein the mounting assembly non-removably couples the channel member to the elongate body.
 14. The adapter assembly of claim 13, wherein the adapter assembly includes a biasing member that is positioned to urge the channel member towards its first position.
 15. A reload assembly comprising: an anvil and a cartridge assembly pivotably coupled to the anvil, the cartridge assembly including a cartridge body, a channel extension and a plurality of staples, the cartridge body having a proximal portion and a distal portion and defining a central knife slot and staple pockets positioned on each side of the central knife slot, each of the plurality of staples received within one of the staple pockets, the channel extension including a base wall and side walls defining a cavity, the cavity receiving the distal portion of the cartridge body, wherein the channel extension is spaced from the proximal portion of the cartridge body.
 16. The reload assembly of claim 15, wherein the anvil includes an anvil body having a proximal portion and a distal portion, the proximal portion of the anvil body including spaced flange portions that define a recess, the proximal portion of the cartridge body received within the recess in the proximal portion of the anvil body.
 17. The reload assembly of claim 16, wherein the proximal portion of the anvil body includes spaced fingers that are positioned within the recess and the proximal portion of the cartridge body defines spaced slots, the spaced fingers received within the spaced slots to pivotably couple the anvil to the cartridge assembly.
 18. The reload assembly of claim 17, wherein the spaced fingers and the spaced slots are curved.
 19. The reload assembly of claim 18, wherein the base wall of the channel extension defines a cutout in a proximal end of the base wall.
 20. The reload assembly of claim 19, wherein the side walls of the channel extension each include a proximally extending finger. 